This invention relates to automatic calling systems and more particularly to apparatus and methods for automatically accessing subscriber line systems through a switched telephone network.
Long distance subscriber systems which compete with the established telephone company's long distance service have now gained wide acceptance. Typically, these systems employ the local switched telephone lines of the established telephone company to connect a subscriber with a computer which then acts to convey the subscriber's call over separately owned long distance microwave networks or the like to a local area where the call is again reintroduced into the local switch telephone network where the same is completed to the location dialed. In such subscriber systems, a user at the subscriber's premises must initially enter a seven digit local telephone number to gain access over the local switched telephone network to a computer which controls the long distance network to be employed. The computer answers the lines and indicates that access has been gained by placing a tone on the line. Upon heating the tone, the user enters a five digit billing code and, thereafter, dials the area code and the phone number of the remote location with which communication is desired. All told, to complete a call over such a computer controlled long distance system, a user at a subscriber's site must input or dial some twenty-two digits in a manner timed to accomodate necessary handshaking with the computer controlling the long distance system. This is time consuming, annoying and often inhibits use.
While automatic dialing equipment, repertory dialers, and the like are well known as exemplified by U.S. Pat. Nos. 3,600,522, 3,694,583, 4,008,380 and 4,126,768, these devices contemplate attachment either to individual telephone sets within a system, or attachment as part of a private telephone system within a subscriber's location or at a central office which provides switching for the telephone system. Many subscriber locations, however, do not comprise large switched private systems but instead take the form of locations having a plurality of telephone lines and a plurality of extensions wherein each such extension has access to several, if not all, of the telephone lines serving that site. For this reason, automatic dialing systems or repertory dialers configured to form a part of a large in-house private switched telephone system do not admit of use with such subscriber's locations and, conversely, the provision of an automatic dialing unit for each extension is excessively costly especially when the same is not cost justified by substantial use.
Subscriber use of separately owned long distance telephone systems also have the attendant disadvantages of being subject to employee abuse and many may not be employed in conjunction with telephone systems where the subscriber has not updated his system from rotary dials to Touch-Tone (a trademark registered to AT&T) or DTMF (Dual Tone Multifrequency) pads. Thus, once an employee has learned the requisite seven digit access code for the computer controlling the private leased line system and his employers billing code therefor, such employee may frequently use the same for his own purposes at locations other than his place of employment. Under these circumstances, it will be appreciated that, while any employer's telephone system is subject to employee abuse, such abuse can usually be controlled within reasonable metes and bounds if use is limited to the work environment. However, once an employee is capable of removing access to such service to a private area, such as the employees home, the subscriber is subject to a much greater degree of abuse. Similarly, since a subscriber's justification for engaging separately owned long distance systems are principally economic, the same may not be reasonably justified if retention of the service imposes an attendant requirement that the subscriber update his telephone service from rotary dials to DTMF pads.
Separately owned long distance subscriber networks are permitted to operate in conjunction with local, telephone company provided service on the basis that the same do not interfere in any manner with the local telephone networks with which they actually interface. More particularly, when a subscriber dials the seven digit code, he effectively employs the telephone system provided by the switched telephone lines to place a local call to a computer controlling the long distance system. The computer then answers and provides a tone, by way of handshaking, so that a user at the subscriber's site may then enter the five digit billing code to identify the subscriber and, thereafter, the area code and the local number to be dialed. The computer acts in response to the area code dialed to transmit the long distance call over the long distance lines maintained for that purpose and reenters the telephone system at a location where the telephone number dialed represents either a local call or a toll call of minor proportion. Thus, in this manner, the separately owned long distance subscriber service provided in no way interferes with the switched telephone networks provided by the telephone companies involved since both entrance and egress to and from the separate system are provided through equipment furnished by the telephone company. There are no special interfaces or equipments provided at the subscriber's office and all actions taken by a user at the subscriber's location occur in a normal mode of use of the telephone system and, in no manner, interferes by way of interface or signal with conventional telephone company equipment. Therefore, it will be readily appreciated by those of ordinary skill in the art that the maintenance of this relationship wherein neither the subscriber nor the company furnishing the separate long distance service introduces any equipment which might adversely effect or otherwise interfere with the normal functions of the switched telephone network is highly desirable and, in fact, is mandated by tariff requirements. Hence, while the provision of automatic dialing equipment to relieve the onerous task of dialing some or all of the twelve digits required for access to a separate long distance system would be highly desirable, the same may in no way interfere with the operation of local telephone equipment and, in a subscriber's location which takes the form of a normal telephone company installation or a comparable system, the same may not require extensive installation of equipment which may interfere with the operation of the subscriber's equipment in either specialized or normal modes of operation nor may such equipment cause a dedication of the subscriber's systems to the operational modes thereof.
Therefore, it is an object of the present invention to provide automatic calling systems and methods therefor for facilitating use of subscriber long distance systems operated through a switched line telephone network.
A further object of this invention is to provide automatic calling systems and methods therefor actuated by entry of code information from a user's handset which code information does not adversely effect the operation of local telephone equipment.
An additional object of this invention is to provide automatic calling systems and methods therefor for use with a subscriber long distance system which does not interfere with the normal operation of telephone equipment when the automatic calling system is not in use.
Another object of this invention is to provide automatic calling systems and methods therefor which are selectively enabled from a user's handset by entry of code information forming a part of the telephone number to be dialed.
A further object of this invention is to provide automatic calling systems and methods therefor which are selectively enabled from a user's handset by entry of code information which is applied to the local telephone system but to which the local telephone system will not respond.
An additional object of this invention is to provide automatic calling systems and methods therefor whose use in conjunction with a separate long distance system which does not require access and billing code information to be disclosed to a user.
Another object of the present invention is to provide automatic calling systems and methods therefor enabling subscriber locations employing rotary dial equipment to provide DTMF codes to a private leased line long distance system.
A further object of the present invention is to provide automatic calling systems and methods therefor suitable for connection to any existing subscriber system without extensive modification of such system.
Various other objects and advantages of the present invention will become clear from the following detailed description of several exemplary embodiments thereof and the novel features will be particularly pointed out in conjunction with the claims appended hereto.